Long term evolution (LTE) defined in 3rd generation partnership project (3GPP) as a standardization project of the cellular communication techniques support a cellular/WLAN interworking technique after a release 12. With the technique, a radio terminal in the RRC connected state or RRC idle state switches bidirectional traffics (network selection and traffic steering) between E-UTRAN and WLAN.
In order to effectively use the cellular/WLAN interworking technique, an introduction of an Xw interface is being discussed. An Xw interface is set between a base station and a wireless LAN termination (WT) for managing a wireless LAN access point. The base station can acquire information related to WLAN (such as information related to AP in the cell of the base station) from the wireless LAN termination (wireless LAN termination node) via the Xw interface.